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<H2><A NAME="8_2">8.2 Bar graphs</A></H2>
<P> Jpgraph also supports 2D vertical bar plots. Before you can use any
 bar plots you must make sure that you included the file
 &quot;jpgraph_bar.php&quot; in your script.</P>
<P> Using bar plots is quite straightforward and works in much the same
 way as line plots which you are already familiar with from the previous
 examples. Assuming you have a data array consisting of the values
 [12,8,19,3,10,5] and you want to display them as a bar plot. This is
 the simplest way to do this:<DIV class="phpscript"><CODE><FONT color="#000000">
 <FONT color="#0000BB">&nbsp;$datay</FONT><FONT color="#007700">=array(</FONT><FONT
color="#0000BB">12</FONT><FONT color="#007700">,</FONT><FONT color="#0000BB">
8</FONT><FONT color="#007700">,</FONT><FONT color="#0000BB">19</FONT><FONT
color="#007700">,</FONT><FONT color="#0000BB">3</FONT><FONT color="#007700">
,</FONT><FONT color="#0000BB">10</FONT><FONT color="#007700">,</FONT><FONT
color="#0000BB">5</FONT><FONT color="#007700">);
<BR></FONT><FONT color="#0000BB">$bplot&nbsp;</FONT><FONT color="#007700">
=&nbsp;new&nbsp;</FONT><FONT color="#0000BB">BarPlot</FONT><FONT color="#007700">(</FONT><FONT
color="#0000BB">$datay</FONT><FONT color="#007700">);
<BR></FONT><FONT color="#0000BB">$graph</FONT><FONT color="#007700">-&gt;</FONT><FONT
color="#0000BB">Add</FONT><FONT color="#007700">(</FONT><FONT color="#0000BB">
$bplot</FONT><FONT color="#007700">);</FONT><FONT color="#0000BB"></FONT>
</FONT></CODE></DIV></P>
<P> If you compare this to the previous line examples you can see that
 the only change necessary was that instead of creating a new line plot
 (via the new LinePlot(...) call) we used the statement new <A href="../ref/BarPlot.html#_C_BARPLOT">
 BarPplot().</A></P>
<P> The other change we should do is to make sure the X-axis have an
 text-scale (it is perfectly fine to use a linear X-scale but in most
 cases this is not the effect you want when you use a bar graph, see
 more below). With this two simple change we will now get a bar graph as
 displayed in the following image
<!--?
Example('example18','A very simple bar graph');
?-->
 You can of course modify the appearance of the bar graph. So for
 example to change the fill color you would use the <A href="../ref/BarPlot.html#_BARPLOT_SETFILLCOLOR">
 BarPlot::SetFillColor()</A> method. Making this small change to the
 previous example would give the expected effect as can be seen in the
 next example.
<!--?
Example('example19','A very simple bar graph with changed fill color');
?-->
<DIV class="note"><B>Note:</B> You should note from the previous two
 graphs that slight change in appearance for the X-scale. The bar graphs
 gets automatically centered between the tick marks when using as text
 x-scale. If you were to use a linear scale they would instead start at
 the left edge of the X-axis and the X-axis would be labeled with a
 linear scale. As is illustrated in the (small) example below.</DIV><DIV class="example">
<BR> <A href="exframes/frame_example19.1.html" target="blank"><IMG border="0"
HEIGHT="100"  src="img/example19.1.png" WIDTH="260"></A>
<BR><B>Figure 29:</B> A small example with a bar graph using a linear
 X-scale <A href="exframes/frame_example19.1.html" target="blank">[src]</A>
&nbsp;
<P></P>
</DIV></P>
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